Ultraviolet protective coating for fabricating epoxy-based components

ABSTRACT

Provided are epoxy-based components and methods of fabricating such components. Specifically, an component comprises an epoxy-based composite part and a UV protective coating disposed over the part. This coating allows for the component to be exposed to UV radiation without any additional coating and without deterioration of the epoxy-based composite part. Specifically, the component may be exposed to interior lights and direct sun during its subsequent fabrication and/or transportation. The UV protective coating comprises polyurethane and silicate filler, such as hydrated aluminum silicate and/or hydrated magnesium silicate. The coating may have a transmittance of less than 1% or even less than 0.1% in the UV range. An epoxy primer layer may be formed directly over the UV protective coating followed by various other coatings, including a decorative finish.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/584,915, filed on May 2, 2017, which is incorporated herein byreference in its entirety for all purposes.

BACKGROUND

Composite materials, such as carbon fiber-reinforced polymers (CFRP),are widely used for fabricating various components due to high strengthand rigidity, low weight, corrosion resistance, and other favorableproperties of these composites. Specifically, many composite materialsare increasingly used in aircraft fabrication, e.g., to form fuselage,wings, tail sections, skin panels, and other components. However, somecomposite materials, especially epoxy-based composites such asepoxy-graphite composites, are ultraviolet (UV) sensitive. Thesecomposite materials may degrade if not protected and exposed UVradiation, such as direct sun exposure and/or interior lighting used onmanufacturing floor, both of which may include some UV radiation.

SUMMARY

Provided are epoxy-based components and methods of fabricating suchcomponents. Specifically, an component comprises an epoxy-basedcomposite part and a UV protective coating disposed over the part. Thiscoating allows for the component to be exposed to UV radiation withoutany additional coating and without deterioration of the epoxy-basedcomposite parts. The UV protective coating protects an epoxy basedsurfacing film as well as epoxy pre-impregnated carbon fiber composite.Specifically, the component may be exposed to interior lights and directsun during its subsequent fabrication and/or transportation. The UVprotective coating comprises polyurethane and silicate filler, such ashydrated aluminum silicate and/or hydrated magnesium silicate. Thecoating may have a transmittance of less than 1% or even less than 0.1%in the UV range. An epoxy primer layer may be formed directly over theUV protective coating followed by various other coatings, including adecorative finish.

In some examples, a method of fabricating an epoxy-based componentcomprises curing an epoxy-based composite part. The epoxy-basedcomposite part comprises a composite base having a surface. Thecomposite base comprises epoxy. The epoxy-based composite part furthercomprises a surfacing film disposed over the surface of the compositebase.

The method proceeds with forming an ultraviolet (UV) protective coatingdirectly over and in contact with at least a portion of the surfacingfilm of the epoxy-based composite part. The UV protective coatingcomprises polyurethane and silicate filler. The silicate fillercomprises a silicate selected from the group consisting of hydratedaluminum silicate and hydrated magnesium silicate. In some examples,both hydrated aluminum silicate and hydrated magnesium silicate arepresent in the UV protective coating. Furthermore, the UV protectivecoating may also comprise titanium oxide. The concentration of thesilicate filler in the UV protective coating may be at least about 20%by weight or, more specifically, at least about 40% by weight.

In some examples, the method further comprises forming an epoxy primerlayer directly over and in contact with the UV protective coating. Themethod may proceed with forming a polyamide-based coating directly andin contact with over the epoxy primer layer. The method may furthercomprise forming a decorative finish directly and in contact with overthe polyamide-based coating. Alternatively, the method may compriseforming a polyurethane topcoat directly over and in contact with thepolyamide-based coating and before forming the decorative finish. Themethod then proceed with forming the decorative finish directly over andin contact with the polyurethane topcoat.

In some examples, the surfacing film remains substantially unexposed toUV radiation after curing the epoxy-based composite part and prior toforming the UV protective coating. For example, the maximum exposurebetween curing the epoxy-based composite part and forming the UVprotective coating may be less than 200 kJ/m² ultraviolet (UV-A)radiation. Furthermore, forming the UV protective coating is performedin an environment substantially free from UV radiation such that theepoxy-based composite part is not exposed to UV radiation while formingthe UV protective coating or UV exposure is minimal such that theepoxy-based composite part remains unaffected. Once the UV protectivecoating is formed over the epoxy-based composite part, the assembly canbe exposed to UV radiation without risk of damaging the epoxy-basedcomposite part.

In some examples, the method further comprises, prior to forming the UVprotective coating, testing the surfacing film of the epoxy-basedcomposite part for UV degradation. For example, this testing may involvewiping the surfacing film with a wipe saturated with acetone andinspecting the wipe for residues. In some examples, the method furthercomprises, prior to forming the UV protective coating, sanding thesurfacing film.

Forming the UV protective coating may comprise spraying a UV protectiveliquid material onto the epoxy-based composite part. Furthermore,forming the UV protective coating may comprise curing the UV protectiveliquid material. Curing the UV protective liquid material may beperformed at a room temperature.

In some examples, the UV protective coating has a thickness of between10 micrometers to 100 micrometers or, more specifically, between 30micrometers to 65 micrometers. Even at such small thicknesses, the UVprotective coating may sufficiently block UV radiation. In someexamples, the UV protective coating has a transmittance of less than 1%in a wavelength range of 100 nanometers and 400 nanometers or, morespecifically, less than 0.1% in a wavelength range of 100 nanometers and400 nanometers.

In some examples, the ultraviolet (UV) protective coating is formed overa portion of the surfacing film of the epoxy-based composite part, whileanother portion of the surfacing film remains exposed. In theseexamples, the method may comprise covering the exposed portion of thesurface layer of the epoxy-based composite part with a protective sheet.

Also provided is an epoxy-based component. The epoxy-based componentcomprises an epoxy-based composite part and an ultraviolet (UV)protective coating. The epoxy-based composite part comprises a compositebase comprising epoxy and having a surface. The epoxy-based compositepart further comprises a surfacing film, disposed over the surface ofthe composite base. The ultraviolet (UV) protective coating may bedisposed directly over and in contact with at least a portion of thesurfacing film of the epoxy-based composite part. The UV protectivecoating may comprise polyurethane and silicate filler. The silicatefiller may comprise a silicate selected from the group consisting ofhydrated aluminum silicate and hydrated magnesium silicate. Theconcentration of the silicate filler in the UV protective coating is atleast about 20% by weight.

In some examples, the epoxy-based component further comprises an epoxyprimer layer, disposed directly over and in contact with the UVprotective coating. The epoxy-based component may also comprise apolyimide-based coating disposed directly over and in contact with theepoxy primer layer. In some embodiments, the epoxy-based componentfurther comprises a decorative finish disposed directly over and incontact with the polyamide-based coating. The epoxy-based component mayalso comprise a polyurethane topcoat and a decorative finish. Thepolyurethane topcoat may be disposed directly over and in contact withthe polyamide-based coating. The decorative finish is disposed directlyover and in contact with the polyurethane topcoat.

In some examples, the UV protective coating has a thickness of between30 micrometers to 65 micrometers. The silicate filler may comprise bothhydrated aluminum silicate and hydrated magnesium silicate. In someexamples, the UV protective coating further comprises titanium oxide.The UV protective coating may have a transmittance of less than 1% in awavelength range of 100 nanometers and 400 nanometers or, morespecifically, less than 0.1% in a wavelength range of 100 nanometers and400 nanometers. The epoxy-based component may be selected from the groupconsisting of a nose section, a tail section, and a middle section.

The features and functions that have been discussed can be achievedindependently in various examples or may be combined in yet otherexamples further details of which can be seen with reference to thefollowing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C are schematic illustrations of different epoxy-basedcomponents, in accordance with some examples.

FIG. 1D is a schematic illustration of the epoxy-based components ofFIGS. 1A-1C forming a fuselage of an aircraft, in accordance with someexamples.

FIG. 2 is a process flowchart corresponding to a method of fabricatingan epoxy-based component, in accordance with some examples.

FIGS. 3A-3E are examples of epoxy-based components at different stagesof the method presented in FIG. 2.

FIG. 4 illustrates UV blocking efficiency of UV protective coatingshaving different thicknesses.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the presented concepts. Thepresented concepts may be practiced without some or all of thesespecific details. In other instances, well known process operations havenot been described in detail so as to not unnecessarily obscure thedescribed concepts. While some concepts will be described in conjunctionwith the specific examples, it will be understood that these examplesare not intended to be limiting.

Introduction

Epoxy-based composites or, more specifically, epoxy-based materialscomprising graphite, which are sometimes referred to as carbonfiber-reinforced plastics, are very strong, lightweight, and have otherdesirable properties. Such composites may be used to fabricate varioustypes of components, such as aircraft components where a combination ofmechanical stress and low weight is highly desirable. However, othertypes of epoxy-based components are also within the scope, such asautomotive parts. The fabricated components can be made into variousgeometric forms and sizes.

The process may involve layering sheets of carbon fiber cloth into amold. The internal cavity of the mold may be shaped as the fabricatedcomponent. The process continues with filling the mold with epoxy andcuring the composite. The epoxy may be a phenol or cresol (e.g.,bisphenol-A) and a crosslinking agent (e.g., epichlorohydrin). The typeand alignment of carbon fibers may be selected to optimize the strengthand stiffness properties of the fabricated component.

One drawback of epoxy-based composites is their IN degradation, inparticular at a 290-400 nm of UV spectrum. This spectrum is comparableto dissociation energies of polymer covalent bonds found in epoxies usedfor composite materials. Specifically, UV radiation absorbed by epoxiescauses photo-oxidative reactions resulting in material degradation,which corresponds molecular weight reduction as well as reduction ofmechanical strength and heat resistance.

Even short periods of IN exposure can change surface morphology ofepoxy-based composites. For example, the surface of a composite mayexhibit a distinct color change from black to dark green. This colorchange may serve as a way for monitoring the degradation process.Changes in surface smoothness may also be observed.

It should be noted that UV radiation is present, at some level, in thesun light and artificial light sources that illuminate manufacturingfacilities. Protecting of epoxy-based fabricated components can bedifficult, in particular when these composites are large structures,such as fuselage components of aircraft. FIGS. 1A-1C are schematicillustrations of different aircraft epoxy-based components 110, inaccordance with some examples. In these examples aircraft epoxy-basedcomponents 110 are nose section 112, tail section 116, and middlesection 114 of aircraft fuselage 100. Aircraft epoxy-based components110 may be processed and receive a UV protective coating prior toassembling these components together, e.g., to form aircraft fuselage100 as, for example, schematically shown in FIG. 1D.

Processing Examples

FIG. 2 is a process flowchart corresponding to method 200 of fabricatingepoxy-based component 110, in accordance with some examples. Someexamples of epoxy-based components are described above and may include anose section, a tail section, and/or a middle section, in some examples.For example, epoxy-based component 110 may be a wing-box. Other examplesof epoxy-based components are also within the scope.

In some examples, method 200 involves curing epoxy-based composite part300 during operation 210. Operation 210 may involve layering sheets ofcarbon fiber cloth (e.g., a prepreg material) into the mold and fillingthe mold with epoxy. In some examples, the sheets are layered using alayup machine, such as an automated tape layup machine. The surface ofthe mold, which received the sheets, may be treated with a release agentor a film. Multiple sheets may be applied one on top of the other untila desired thickness is achieved and desired orientation of thereinforcement fibers is achieved for maximum strength and efficiency. Insome examples, the layered structure is subjected to an optionalpre-cure vacuum hold under a vacuum pressure. Operation 210 may theninvolve heat curing epoxy-based composite part 300 in a heatingapparatus (e.g., an autoclave). The heat curing may be performed undervacuum. The temperature and duration of heat curing depends on epoxyused for epoxy-based composite part 300 and other factors.

Referring to FIG. 3A, epoxy-based composite part 300 may comprisescomposite base 302 having surface 304. Composite base 302 may be anepoxy prepreg resin having carbon fibers disposed within. The carbonfibers may be in a woven fabric form. More specifically, epoxy-basedcomposite part 300 may be a carbon fiber reinforced polymer composite(CFRP). In some examples, epoxy-based composite part 300 comprisessurfacing film 306. The composition of surfacing film 306 may bedifferent from the composition of composite base 302. For example,surfacing film 306 may have a higher concentration of epoxy thancomposite base 302, e.g., a resin-rich shell that blocks fiberread-through and enhances paint adhesion. In some examples, surfacingfilm 306 may comprises a different polymer than composite base 302,e.g., polyurethane/polycarbonate, polyester, and the like.

Method 200 may also involve testing surfacing film 306 of epoxy-basedcomposite part 300 for UV degradation during optional operation 212. Forexample, operation 212 may involve wiping surfacing film 306 with wipe305, referring to block 214 in FIG. 2 and a schematic illustration inFIG. 3A. Wipe 305 may be saturated with acetone. For example, the samespot on epoxy-based composite part 300 may be wiped between 10-20 timesusing a heavy hand pressure.

Operation 212 may also involve inspecting wipe 305 for residues,referring to block 216 in FIG. 2. FIG. 3A is s schematic illustration ofsurfacing film 306 being wiped with wipe 305. It would be understoodthat if optional operation 212 is performed, operation 212 is performedprior to forming UV protective coating 310 during operation 220.

Without being bound to any particular theory, it is believed that UVdegradation of epoxy-based composite part 300 may produce quinone,hydroquinone, or alkyl ketone products on the surface. This may resultin discoloration of the surface or, more specifically, producing greenresidue on the surface of epoxy-based composite part 300. Wiping duringoperation 214 may transfer this residue to from the surface to wipe 305.Furthermore, small amounts of residue may not detectable directly on thesurface but when concentrated on wipe 305, this residue may be moredetectable. For example, the same wipe 305 may be used to wipe a largearea of the surface.

Method 200 may also involve sanding surfacing film 306 during optionaloperation 218. Sanding surfacing film 306 may be used to remove anyresidue resulting from UV degradation of epoxy-based composite part 300.Furthermore, sanding surfacing film 306 may increase the surfaceroughness of surfacing film 306 to improve bonding to UV protectivecoating 310. It would be understood that if optional operation 218 isperformed, operation 218 is performed prior to forming UV protectivecoating 310 during operation 220.

Returning to FIG. 2, method 200 may proceed with forming UV protectivecoating 310 during operation 220. UV protective coating 310 may beformed directly over and in contact with at least a portion of surfacingfilm 306 of epoxy-based composite part 300 as, for example, shown inFIG. 313. FIG. 313 is a schematic illustration of epoxy-based component110 after completing operation 220. At this stage, epoxy-based component110 comprises epoxy-based composite part 300 with UV protective coating310 disposed over epoxy-based composite part 300. If epoxy-basedcomposite part 300 comprises surfacing film 306, then UV protectivecoating 310 may be disposed over surfacing film 306 or, morespecifically, directly over and in contact with surfacing film 306. Ifepoxy-based composite part 300 does not have surfacing film 306, then UVprotective coating 310 may be disposed over composite base 302 or, morespecifically, directly over and in contact with composite base 302.

UV protective coating 310 comprises polyurethane 312 and silicate filler314, such as hydrated aluminum silicate and/or hydrated magnesiumsilicate. The concentration of silicate filler 314 in UV protectivecoating 310 may be at least about 20% by weight or, more specifically,at least about 40% by weight. In some examples, silicate filler 314 isuniformly distributed throughout the entire volume of UV protectivecoating 310. Likewise, polyurethane 312 may be uniformly distributedthroughout the entire volume of UV protective coating 310. For purposesof this disclosure, the term “uniformly distributed” means that theconcentration of a component varies by less than 10 weight % throughoutthe entire volume.

UV protective coating 310 may have a thickness of between 10 micrometersto 100 micrometers of, more specifically, between 30 micrometers to 65micrometers. As further described below with reference to FIG. 4, UVprotective coating 310 provides sufficient blockage of UV radiation evenat such low thicknesses. Furthermore, a lower thickness of UV protectivecoating 310 corresponds to a lower added weight to a subassemblycomprising UV protective coating 310, which may be important foraircraft applications.

Silicate filler 314 of UV protective coating 310 may comprise one orboth hydrated aluminum silicate (e.g., kaolin) and hydrated magnesiumsilicate (e.g., talc). In some examples, UV protective coating 310further comprises titanium oxide. UV protective coating 310 may comprisesilica.

Forming 220 UV protective coating 310 may comprise spraying a UVprotective liquid material (block 222 in FIG. 2). However, otherdisposition techniques, such as brushing, rolling, and the like are alsowithin the scope. In some examples, the UV protective liquid materialincludes one or more acetates, such as n-butyl acetate and/or2-methoxy-1-methylethyl acetate.

Forming 220 UV protective coating 310 may also comprise curing the UVprotective liquid material (block 224 in FIG. 2). Curing operation 224may be performed at a room temperature. The curing duration may bebetween about 0.5 hours and 2 hours.

In some examples, surfacing film 360 remains substantially unexposed toUV radiation after curing of epoxy-based composite part 300 duringoperation 210 and prior to forming UV protective coating 310 duringoperation 220. For example, maximum exposure between the curingoperation and the UV protective coating forming operational may be lessthan 200 kJ/m² ultraviolet UV-A radiation or even less than 100 kJ/m²ultraviolet UV-A radiation. Furthermore, forming UV protective coating310 during operation 220 may be performed in an environmentsubstantially free from UV radiation (e.g., a manufacturing facilitywith a special lighting). These features ensure that epoxy-basedcomposite part 300 does not experience UV degradation before forming UVprotective coating 310.

Method 200 may proceed with forming epoxy primer layer 320 duringoptional operation 230. Epoxy primer layer 320 may be formed directlyover and in contact with UV protective coating 310. Epoxy primer layer320 may comprise one or more polyfunctional amine-containing compoundsor a bisphenol-A-diglycidyl ether (e.g., cured with triethylenetetramine). For example, an epoxy resin dissolved in tert-butyl acetatemay be used to form epoxy primer layer 320.

Method 200 may proceed with forming polyamide-based coating 330 duringoptional operation 240. Polyamide-based coating 330 may be formeddirectly and in contact with over epoxy primer layer 320.

Method 200 may involve forming polyurethane topcoat 340 during optionaloperation 250. Polyurethane topcoat 340 may be formed directly over andin contact with polyamide-based coating 330.

Method 200 may involve forming decorative finish 350 during optionaloperation 260. Decorative finish 350 may be formed directly and incontact with polyamide-based coating 330. Alternatively, decorativefinish 350 may be formed directly and in contact with polyurethanetopcoat 340, if polyurethane topcoat 340 was previously formed.

Epoxy-Based Component Examples

FIG. 3C is a schematic illustration of epoxy-based component 110comprising epoxy-based composite part 300, UV protective coating 310disposed over epoxy-based composite part 300, epoxy primer layer 320disposed over UV protective coating 310, polyamide-based coating 330disposed over epoxy primer layer 320, polyurethane topcoat 340 disposedover polyamide-based coating 330, and decorative finish 350 disposedover polyurethane topcoat 340. It should be noted that even though oneor more of polyamide-based coating 330, polyurethane topcoat 340, anddecorative finish 350 may provide UV protection once these layers areformed, UV protective coating 310 remains as a part of epoxy-basedcomponent 110. As such, UV protective coating 310 provides UV protectionuntil though one or more of polyamide-based coating 330, polyurethanetopcoat 340, and decorative finish 350 are formed. Furthermore, UVprotective coating 310 allows using additional options for one or moreof polyamide-based coating 330, polyurethane topcoat 340, and decorativefinish 350 that may not have been previously available since epoxy-basedcomposite part 300 is already protected from UV degradation by UVprotective coating 310.

FIG. 3C is a schematic illustration of another example of epoxy-basedcomponent 110 that does not have polyurethane topcoat 340. In thisexample, UV protective coating 310 is also disposed over epoxy-basedcomposite part 300, epoxy primer layer 320 is disposed over UVprotective coating 310, polyimide-based coating 330 is disposed overepoxy primer layer 320. However, decorative finish 350 is disposeddirectly over and interfaces with polyamide-based coating 330.

FIG. 3D illustrates another example where epoxy-based composite part 300is only partially covered with UV protective coating 310. As such,epoxy-based composite part 300 has exposed portion 307, which may beprotected from UV degradation by other means.

In general, epoxy-based component 110 may comprises at least epoxy-basedcomposite part 300 and UV protective coating 310. Epoxy-based compositepart 300 may comprise composite base 302, having surface 304. In someexamples, epoxy-based composite part 300 also comprises surfacing film306, disposed over surface 304 of composite base 302. Alternatively,epoxy-based composite part 300 may not have surfacing film 306.

UV protective coating 310 may be disposed directly over and in contactwith at least a portion of surfacing film 306, if surfacing film 306 ispresent. If surfacing film 306 is not present, then UV protectivecoating 310 may be disposed directly over and in contact with at least aportion of composite base 302.

UV protective coating 310 may comprise polyurethane 312. Furthermore, UVprotective coating 310 may comprise silicate filler 314, such ashydrated aluminum silicate and hydrated magnesium silicate. In someexamples, UV protective coating 310 both hydrated aluminum silicate andhydrated magnesium silicate. The concentration of silicate filler 314 inUV protective coating 310 may be at least about 20% by weight or, morespecifically, at least about 40% by weight. In some examples, UVprotective coating further comprises titanium oxide.

UV protective coating 310 may have a thickness of between 10 micrometersand 100 micrometers or, more specifically, between about 30 micrometersto 65 micrometers. UV protective coating 310 may have a transmittance ofless than 1% in a wavelength range of 100 nanometers and 400 nanometersor, more specifically, less than 0.1% in a wavelength range of 100nanometers and 400 nanometers.

Experimental Data

FIG. 4 illustrates experimental data showing UV blocking efficiency ofUV protective coatings having different thicknesses. All UV protectivecoatings had the same composition and were applied using the same spraytechnique. Specifically, the UV protective coatings included bothhydrated aluminum silicate and hydrated magnesium silicate and titaniumoxide.

Line 405 corresponds to a UV protective coating having a thickness of 13micrometers (0.5 mils). Line 410 corresponds to a UV protective coatinghaving a thickness of 25 micrometers (1.0 mils). Line 420 corresponds toa UV protective coating having a thickness of 50 micrometers (2 mils).Finally, line 430 corresponds to a UV protective coating having athickness of 76 micrometers (3 mils). It has been found that even verythin UV protective coatings sufficiently block UV radiation for theentire range. Specifically, the thinnest test sample was only 13micrometers thick and has a transmittance rate of less than 0.5% for theentire UV range.

Conclusion

Although the foregoing concepts have been described in some detail forpurposes of clarity of understanding, after reading the above-disclosureit will be apparent that certain changes and modifications may bepracticed within the scope of the appended claims. It should be notedthat there are many alternative ways of implementing the processes,systems, and self-aligning riveting tools. Accordingly, the presentexamples are to be considered as illustrative and not restrictive.

In the above description, numerous specific details are set forth toprovide a thorough understanding of the disclosed concepts, which may bepracticed without some or all of these particulars. In other instances,details of known devices and/or processes have been omitted to avoidunnecessarily obscuring the disclosure. While some concepts will bedescribed in conjunction with specific examples, it will be understoodthat these examples are not intended to be limiting.

What is claimed is:
 1. An epoxy-based component comprising: anepoxy-based composite part, comprising a composite base, wherein thecomposite base comprises epoxy and a surface; and an ultraviolet (UV)protective coating, disposed directly over and in contact with at leasta portion of the epoxy-based composite part, wherein: the UV protectivecoating comprises a polyurethane polymer and silicate filler, the UVprotective coating has a transmittance of less than 1% in a wavelengthrange of 100 nanometers to 400 nanometers, the silicate filler comprisesa silicate selected from the group consisting of hydrated aluminumsilicate, hydrated magnesium silicate, and mixtures thereof, and aconcentration of the silicate filler in the UV protective coating is atleast 20% by weight.
 2. The epoxy-based component of claim 1, furthercomprising an epoxy primer layer, disposed directly over and in contactwith the UV protective coating.
 3. The epoxy-based component of claim 2,further comprising a polyimide-based coating, disposed directly over andin contact with the epoxy primer layer.
 4. The epoxy-based component ofclaim 3, further comprising a decorative finish disposed directly overand in contact with the polyimide-based coating.
 5. The epoxy-basedcomponent of claim 3, further comprising: a polyurethane topcoatdisposed directly over and in contact with the polyimide-based coatingand a decorative finish disposed directly over and in contact with thepolyurethane topcoat.
 6. The epoxy-based component of claim 1, whereinthe UV protective coating has a thickness of between 10 micrometers to100 micrometers.
 7. The epoxy-based component of claim 1, wherein the UVprotective coating has a thickness of between 30 micrometers to 65micrometers.
 8. The epoxy-based component of claim 1, wherein thesilicate filler comprises both hydrated aluminum silicate and hydratedmagnesium silicate.
 9. The epoxy-based component of claim 1, wherein theUV protective coating further comprises titanium oxide.
 10. Theepoxy-based component of claim 1, wherein the UV protective coating hasa transmittance of less than 0.1% in a wavelength range of 100nanometers to 400 nanometers.
 11. The epoxy-based component of claim 1,wherein the concentration of the silicate filler in the UV protectivecoating is at least 40% by weight.
 12. The epoxy-based component ofclaim 1, wherein the UV protective coating further comprises silica. 13.The epoxy-based component of claim 1, wherein the epoxy-based compositepart further comprises a surfacing film, disposed over the surface ofthe composite base, and wherein the UV protective coating is disposeddirectly over and in contact with at least a portion of the surfacingfilm.
 14. The epoxy-based component of claim 13, wherein an additionalportion of the surfacing film is free from contact with the UVprotective coating.
 15. The epoxy-based component of claim 1, whereinthe UV protective coating is disposed directly over and in contact withthe surface of the composite base.
 16. The epoxy-based component ofclaim 1, wherein the epoxy-based component is an aircraft component. 17.The epoxy-based component of claim 1, wherein the epoxy-based componentis selected from a fuselage component and a wing-box.
 18. Theepoxy-based component of claim 1, wherein the epoxy-based composite partcomprises an epoxy prepreg resin and carbon fibers disposed within theepoxy prepreg resin.
 19. The epoxy-based component of claim 17, whereinthe carbon fibers are in a form of a woven fabric.
 20. The epoxy-basedcomponent of claim 1, wherein the UV protective coating is depositedfrom a liquid comprising at least one of n-butyl acetate or2-methoxy-1-methylethyl acetate.